gearbox/countershaft sprocket torque?

How in the world do you measure the 60 or 80 ftlbs of torque on this? Is there a socket actually big enough to fit over the shaft, or do you guys just wrench the hell out of it? :?:

I haven't found a socket quite deep enough yet. One of these days I'm gonna cut and weld one up for that. In the mean time I have a big box wrench that I yank on whilst holding the rear brake with my foot. Luckily there's a lock tab washer there, so tourque isn't critical.

Autozone has a 1 1/2 " deep socket for $9.99. I purchased 2 of them. I took one cut the top off with a chop saw. I ground the edges to fit square and some relief to except a weld. I welded them 2 together and now have a very deep socket. It works.